This file enables you to test build orders and practice your starting build. You start off at a starting point on the map and it gives you 6 scvs/probes/drones and you can test your build order. If you want to try again, you just use the hotkeys to restart and try again. You are able to see how long your last build took, how much minerals/gas you extracted in that time and what your supply was.

Start up the map editor (StarCraft II Editor.exe) found in your StarCraft II Installation Directory. Use it to open the map file found in the .zip download and then use CTL-F9 to start up the game and run the map.